Investigation of the Closure and Simplified Green's Function Approximations in Second-Order Distorted-Wave Calculations for the (e, 2e) Processes
Triple-differential cross sections for electron impact ionization of helium at 102 eV are presented for both coplanar and perpendicular plane asymmetric geometries within the framework of second-order distorted-wave theory. The closure approximation and the simplified Green's function approximation, which are currently used in the evaluation of the second-order amplitudes, are investigated and the accuracy of the approximations is examined. It is found that second-order effects are significant for this incident energy and the simplified Green's function approximation is generally more valid than the closure approximation.
Z. Chen et al., "Investigation of the Closure and Simplified Green's Function Approximations in Second-Order Distorted-Wave Calculations for the (e, 2e) Processes," Journal of Physics B: Atomic, Molecular and Optical Physics, Institute of Physics - IOP Publishing, Jun 2007.
The definitive version is available at http://dx.doi.org/10.1088/0953-4075/40/12/009
National Science Foundation (U.S.)
Keywords and Phrases
Atomic Excitation; Atomic Ionization; Atomic Physics; Molecular Physics; Statistical Theories; Stochastic and Trajectory Models; Transition State
Article - Journal
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